Saturday 9 March 2013

Update (1) Nuclear

Time for my monthly update. Usually I squash too much into one post so I thought this time, with it being a special time, I'd spread it out a bit. Today I'll look at the reactor and tomorrow the evacuees.

This last week or so restrictions on media access to Fukushima Daiichi and the exclusion zone seem to have been eased so we've been treated to shots of well known TV presenters donning white overalls and helmet-cum-gas mask headwear and clambering around Reactor 4. Helicopters are allowed to fly lower so we see lots of before and after pictures and Google has even driven a car round Namie so you'll be able to see the ghost town on Street View this summer.

But back to the reactors. Reactor 1 is covered over with a white roof (levels outside 300 μSv/hr, levels inside: 11 Sv/hr), Reactor 2 is the only one with the building intact (levels inside: 72 Sv/hr), Reactor 3 badly damaged but with the debris being removed (no success yet in measuring levels inside), and at Reactor 4 that unstable roof has been removed and a structure is being built alongside to take the cranes etc. which will remove the spent fuel stored there, work which will start in November. (Radiation in Reactor 4 is not at fatal levels as the reactor was not in operation and contained no fuel at the time of the disaster.)

The three reactors which suffered meltdown continue to be cooled with water which circulates in a self contained system. The trouble is that underground water - from the ground, from rain - leaks through cracks into the floor of all four reactors and has to be removed. At the rate of 400 tons a day. The water is treated: it has the caesium and salt removed, and then it's stored in tanks, solid metal tanks, each containing 1,000 tons of water. At present there is 260,000 tons of water stored on site. Before the disaster the plant was backed by a large wood but the trees have been chopped down to make way for more tanks. A facility (called ALPS) is being built to treat the water further and remove 62 kinds of radioactive material leaving just one. Diluting this and dumping the water in the sea is one solution but it's controversial.

Watching the footage on TV one is struck by how many people, all in their white boiler suits, there are working at the plant. Seems a busy place. The work is ahead of schedule and the plan is to have all the spent fuel assemblies (over 6,000) removed from all four reactors by 2021. Then they will start on the big one: removing the melted fuel from reactors 1 to 3. Next year they are to build a mock up to start practising. 

This new government revoked the earlier government's pledge to fade out nuclear power by 2030. But the new regulatory body is insisting on new safety standards. These will be finalised in July but the electric companies then  have to comply so it may be two years before any return to operation. The other bete noire of the NRA, is reactors built on earthquake faultlines so the one plant currently in operation may have to close.

Meanwhile 90% of Japan's energy comes from fossil fuels, most of it imported LNG. The weak yen is good for exporters but petrol has gone up and electricity prices, which rose in Tokyo last year, are set to rise in the rest of the country, including here, in the summer. 

Yangida Kunio was on TV tonight. He's a non-fiction writer who's specialised in aeroplane accidents and he made the point that the difference between a million to one risk of an aircraft or machine breaking down and a million to one chance of a nuclear accident is in the length of time and cost it takes to remedy, and the wide extent of the damage. At Fukushima communities in a 20 to 30 km radius have lost everything.
Food for thought.

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